高寒草甸土壤CO_2和N_2O释放对C、P添加的响应

Responses of CO_2 and N_2O emissions to carbon and phosphorus additions in alpine meadow soil on the Qinghai-Tibetan plateau

【目的】探明碳、磷输入对土壤CO_2和N_2O排放的影响.【方法】以青藏高原高寒草甸土壤为研究对象,采用室内培养的方法,设置3个处理(C:碳添加;P:磷添加;CP:碳磷共同添加)和1个对照(CK),研究了碳、磷单独添加以及共同添加对高寒草甸土壤CO_2和N_2O释放的影响.【结果】碳素单独添加或碳、磷共同添加均显著增加了高寒草甸土壤微生物生物量碳(MBC)和微生物生物量氮(MBN)的含量,而磷素单独添加对其影响不显著;碳素单独添加或碳、磷共同添加均显著增加了高寒草甸土壤CO_2和N_2O的释放量,而磷素单独添加对其影响不显著;高寒草甸土壤CO_2释放量与土壤DOC含量呈显著正相关关系;高寒草甸土壤N_2O的产生过程以反硝化作用为主.【结论】不同处理CO_2和N_2O的全球增温潜能(GWP)由大至小顺序为:CP>C>P>CK.

[Objective] An incubation experiment in laboratory was conducted to examine the effects of the carbon （C） and phosphorus （P） additions on carbon dioxide （CO2） and nitrous oxide （N20） emissions from the soil sampled on Qinghai-Tibetan Plateau. [Method] Four treatments were adopted in this study, included the control （CK） and three treatments of additions （carbon, phosphorus, carbon and phosphorus）. [Result] The carbon added individually or carbon,phosphorus add together significantly increased soil mi eroorganisms C （MBC） and N （MBN） content,but the phosphorus added individually was not significant. Carbon added individually or carbon, phosphorus add together were significantly increased the alpine mead- ow soil CO2 and N20, but the phosphorus added individually was not significant. Data analysis revealed a significant positive correlation between the cumulative CO2 emissions and the soil DOC concentration. Soil N20 production was mainly controlled by denitrifieation. [Conclusion] The variation of global warming po tential （GWP） of CO2 and N20 for the carbon （C） and phosphorus （P） addition was：CP〉C〉P〉CK.